Chagos News The Periodical Newsletter of the Chagos Conservation Trust and Chagos Conservation Trust US No 57 December 2020

ISSN 2046 7222 © Jon Slayer

Contents © Jon Slayer Editorial

Dr Natasha Gibson, CCT Chair

By now, I’m sure all of you have watched oceans and coasts means reducing the Editorial P3 David Attenborough’s moving testament pressure on those ecosystems so they can to environmental change and habitat recover, both naturally and by re-seeding or destruction in his reflections on a Life transplanting key species”. on our Planet. “Scientist David”, as my The Story of the Lost Brain P4 young son calls him, not only documented The science of biodiversity monitoring has the natural world in stunning detail but recently stepped up a gear with a new implored all of us to care for it through monitoring tool: environmental DNA analysis. News in brief P10 small actions and large efforts. This is described in more detail on P16 by the And so, in the spirit of this citizen science, I’ve scientists of NatureMetrics, who we hope to stepped up to the challenge of chairing CCT in partner with on the , but in A Decade in Review P12 this exciting time as it implements the Healthy basic terms the tool picks up traces of Islands, Health Reefs programme. and plants from water, sediment, or soil.

I hope that my extensive experience in This vastly increases the ability to determine Next Steps Towards a Rewilded P14 formulating and leading rehabilitation, what species are present in an area, to detect biodiversity, clean energy, and sustainability rare and elusive organisms, and is more cost Archipelago programmes will benefit the Trust and effective as it relies on sample collection its ambitions. rather than direct observation of numbers.

Next year will be an important milestone year These samples can be collected by anyone New Tools for Monitoring Biodiversity P16 for CCT with the launch of Healthy Islands, as it is a straightforward process, which is Healthy Reefs. a bonus for CCT as we can ask any visiting scientific expedition, or even personnel based This is an ambitious 10-year programme to on , to take these on our behalf. rewild the Chagos Archipelago, and is our contribution to the UN Decade on Ecosystem Thank you again for your continued interest Restoration that aims to prevent, halt and and support, especially through a difficult reverse the degradation of ecosystems on year due to the global pandemic, and all of every continent and in every ocean. us here at CCT look forward to updating you next year on the progress of Healthy Islands, Our programme aims to eradicate invasive Healthy Reefs. species and allow the reintroduction of seabirds and native vegetation, and so supports the UN’s statement that “restoring Wishing you a safe and happy 2021! © Jon Slayer Cover image: Chagos chagius © Amelia Rose/University of Oxford 2 3 Professor Charles Sheppard, a wonderful On the third day’s sail, the vessel arrived at Ile character known to many at CCT and in my Diamant to anchor for a day or two, whilst we romantic mind, a passionate marine scientist used the inflatable boats to survey the reefs straight out of the rumpled pages of my copy of the islands nearby. At the seaward sites of of The Lost World. Ile de la Passe and Ile Diamant, I continued to search for and sample the abundant As the warm winds tugged at our hair (well, and Porites species which form the focus of certainly mine, at any rate), Charles was our research into health at Oxford, whilst regaling me with glorious and nostalgic always keeping half an eye out for Ctenella. chronicles of his time diving in the Chagos Archipelago in the 1970s, and the tragic The occasional surge of hope was more demise of one of its most iconic denizens, often than not a false one, colonies of similar- the Chagos brain coral (Ctenella chagius), looking brain Goniastrea and Leptoria Figure 1 © Amelia Rose/University of Oxford an endemic to this region of the world. easy to mistake at depth. That afternoon, buffeted by a slight swell, we skipped As he eloquently described in his article across the waves to anchor just off Moresby for CCT several years ago (‘The Chagos Island, named after the eighteenth century brain coral Ctenella chagius: falling into cartographer who surveyed these islands. the red’; Chagos News, No. 52 July 2018), The Story of the this beautiful hemispherical coral (Figure 1) The site comprised a wide terrace at six was once one of the most common in the metres depth, sloping down to 11 metres and Lost Brain Coral archipelago. then dropping off–it was a wonderful place, Dr Bryan Wilson, Department of Zoology, and with hindsight, one of my favourite on However, recent warming events in the Indian that expedition, with high coral cover and University of Oxford Ocean have disproportionately decimated diversity. And yet also a challenging dive, its once abundant populations, such that the subsurface current increasing steadily on a previous expedition to BIOT in 2017, throughout the hour underwater. Employing As a child, I was entranced by the world and conserve the species for posterity not a single live colony was found and there my usual survey tactic of heading upcurrent to fantastical fictional tales of Conan Doyle’s and eventual reintroduction back into its were fears that it had become extinct. Upon begin and then drift-diving back to the anchor, The Lost World, and later, by its real-life jungle home. their return to the archipelago the following my research associate (Amelia Rose) and I (and admittedly slightly less exotic but year however, a small number of diminished finned across the reef looking for corals to nonetheless enthralling) counterpart, the Despite it being the 1980s, those dreams extant living fragments were discovered in the sample and tag. telling of Marjorie Courtney-Latimer’s always seemed to be illuminated by Victorian northern of Salomon and , rediscovery of the long thought extinct flash photography, possibly in tribute to the and with it, the chance that the species was And within the first ten minutes, we spotted coelacanth, amongst a rotting waste tall tales of that time, who knows. Of course, not lost to science after all. our first glimpse of the enigmatic Ctenella, pile of landed fish on the docks of East that was some decades ago and whilst my albeit a very pale and sorry-looking fragment, After hearing this and forever being the London, South Africa in 1938. dreams have become slightly jaded by the a small surviving part of what was once a realisation of the hundreds of extinctions that optimist, I had on something of a whim much larger colony (Figure 2) and likely one In my frequent young flights of fancy, I often have happened since my childhood, I have included a permit for Ctenella when applying of the specimens that Charles had spotted the imagined myself some great explorer of old, always held on to that same bookwormish to the BIOT Administration to sample for a year before. Six more similarly sorry-looking pushing through dense undergrowth into a fantasy. And then, several decades later, I number of other more commonly-occurring findings followed and I couldn’t help but be jungle clearing, only to see the merest flash finally took that flight of fancy... coral species, on the off chance (nay, the slightly underwhelmed–and terribly sad. of something disappearing into the thicket–the inspired hope!) that I would stumble upon one striped tail of a thylacine, the flecked breast Early in April 2019 and having only just joined on my upcoming dives. The photos Charles had showed me were of a Mauritius kestrel, or possibly even the the Bertarelli Program in Marine Science of pink-hued and beachball-sized giant As luck would have it, our expedition began comedically portly rump of a dodo. (BPMS) several months before, I found underwater brains and these fragments myself on their annual expedition to the in the south-west corner of Peros Banhos were mere shadows of those. Still, where I And then the furious chase that followed British Indian Ocean Territory (BIOT), aboard , surveying Ile du Coin, and as we sailed could, I tagged the colonies and gently took (possibly more of a clumsy lunge in the case the Patrol Vessel Grampian Frontier, forcing steadily northwards and clockwise in the thumbnail-sized tissue samples for which of the dodo). The capture! And the return its way through an unseasonable Indian coming days, my anticipation to dive the I’d so optimistically applied for a permit home a hero, to share my discovery with the Ocean surge and chatting up on deck with northern islands of the atoll grew. those months before, in the hope that some

4 5 contribution to the paucity of knowledge fortune, I was lucky enough to be awarded concerning this little coral could be made. a global research award to do just that by QIAGEN, one of the world’s leading The six or seven weeks that followed our biotechnology companies. And as I write this, return to the UK were nervous ones–far too I have received the first results back, and am many times in my career have samples gone currently delving into the first ever genome missing or spoiled during their inexorable data for this coral, hoping that the secrets of progress home around the globe–the its enigmatic and tenuous existence might sensation heightened by the thoughts that finally be revealed. given another unparalleled warming event in the central Indian Ocean, that these could be Buoyed up by last year’s finding, in the last samples of this coral ever taken. February of this year, I headed out once again on the annual BPMS expedition to But arrive they did and in unspoiled condition, BIOT, little knowing the global chaos that in a toughened-plastic trunk festooned with would soon ensue. permits and airline stickers, where they were immediately transferred to the -80C freezer in Arriving just before the main expedition our molecular lab at the University of Oxford’s team, our first week was to be based on John Krebs Field Station for safekeeping. the island of Diego Garcia (DG), assessing its feasibility to be an ecological study site So very little is known about Ctenella, and all representing the wider (and less easily that is comes from Charles’ sterling work in accessible) archipelago. recent decades, so almost anything that we learn will add to our knowledge of the coral. It was hoped that we might find Ctenella around DG, but that was tempered by the Therefore, with the tissue samples I had very real expectation that was it was highly collected, I fervently hoped I might be able to unlikely we would do so. Fortune however extract enough DNA to sequence its genome– favours the brave, and only our second and some months later, by incredible good dive of the expedition, at the seaward side

Figure 2 © Bryan Wilson/University of Oxford Figure 3 © Margaux Steyaert/University of Oxford/ZSL

6 7 of Barton Point at the northern end of the of the expedition joined us on the Grampian of Ctenella (Figure 5), dark-coloured and queer, my body tingled. I stood as if stricken island, we dropped over the boat’s side into a Frontier and we sailed northwards and up apparently healthy. to stone.”1 rough swell and literally on top of the largest through the archipelago. Ctenella colony I had yet seen, a full and As my heart began to race, Margaux spotted And on what was my first dry St Patricks beautifully coloured hemisphere likely five to My sombre mood was exacerbated by another–and then two more several metres Day in decades, as our inflatable made its ten years old, an incredible sight to behold. distressing reports that were beginning to further along. steady way back to the Grampian Frontier come in from around the globe that a novel for a journey home to a suddenly uncertain From one of the leading edges of the colony, coronavirus had taken hold in an increasing All in all we spotted some fifteen colonies world, I elatedly realised that I knew exactly I took a small tissue sample as before (Figure number of countries and that national borders in that hundred metre swim back to the boat, how he felt that day in 1938. And that I’d been 3), whilst warily looking over my shoulder at were suddenly springing shut worldwide. my depleted air supply diminishing faster awaiting that feeling my entire life. a large grey reef shark lurking almost out of still in the heady rush of my childlike sight some thirty metres behind in the gloom Two days before the expedition was excitement as we swam overhead just below Where there was none before, there is real (Figure 4). summarily aborted and we were ordered to the surface, in what to my mind was an tangible hope now borne that this – make for the with unseemly haste, Aladdin’s Cave of Ctenella richer than any I and others unexplored in the archipelago– My Reef0 team (comprising Margaux Steyaert the expedition team found themselves on could have imagined. might offer a last stronghold for the species, and Vivian Cumbo) and I enthusiastically what would unknowingly be one of our last a refugia for this critically endangered and searched for more colonies in the tens of dives in the Chagos Archipelago; Middle The very fact that this happened in the last iconic coral, especially given that these metres around this colony, but to no avail, Brother Island, one of the Three Brothers in minutes of our final dive here, low on air and colonies would predate the recent warming and the earlier nascent joy of the dive soon the centre of the Great Chagos Bank. knowing that we were steaming northwards events in the region. ebbed away. the following day, unsure as to when we Margaux and I had just completed a survey of would next return, made the surface swim Where we find viable populations, there exists For this coral to survive and reproduce, Middle Brother Lagoon, a wonderfully sandy back that much more bittersweet. a chance that the coral can be conserved teetering on the edge of extinction as it is, and protected basin replete with large puppy- and recovered, and whilst that chance might there needs be a biologically viable population like grey nurse sharks, and close to our safe J. L. B. Smith (the amateur ichthyologist indeed be slight, as Charles so optimistically of colonies within suitable spawning distance air limit for surfacing, were making our way who confirmed Marjorie Courtney-Latimer’s ended his 2018 article, “...we must still try!” of each other and this sadly was not it. back along a reef wall to the inflatable boats Coelacanth discovery) once wrote of his 1 anchored nearby. feelings that momentous day, when he Old Fourlegs: The Story of the Coelacanth by J.L.B. Smith. New Indeed, no further colonies were seen in the realised what lay before him: “Although I had York: Longmans, Green & Co., 1956 surveys around DG that week, nor in the And there, in the shadows of the base of come prepared, that first sight hit me like a coming days after the remaining members the wall, were two unmistakable colonies white-hot blast and made me feel shaky and

Figure 4 © Vivian Cumbo/University of Oxford Figure 5 © Bryan Wilson/University of Oxford

8 9 News in brief Slayer Jon ©

© Dr Mike Pienkowski, UKOTCF © Jon Slayer © Grant Harper © UKOTCF

New marine protection Future funding for corals Rats evicted from paradise Staying Connected for Conservation conference The government of Tristan da Cunha CCT was invited to participate in a high- Palmyra had been an isolated and has announced it will extend its existing level meeting to discuss The Global tranquil Pacific atoll until an invasion of The UK Overseas Territories environmental protections to safeguard Fund for Coral Reefs. black rats set its ecology hurtling down a Conservation Foundation has a huge diversity of wildlife, including different path. announced its online conference penguins, whales, sharks and seals, The Fund seeks to raise and invest USD ‘Staying Connected for Conservation in by creating an almost 700,000 square $500 million in conservation Approximately 20,000 rats lived on a Changed World’, to be held over four kilometre marine reserve. over the next 10 years through a Palmyra; a density around 10 times days in March 2021. coalition between United Nations higher than in cooler climates thanks to It will be the planet’s fourth largest, agencies, financial institutions and the tropical environment. The conference will cover subjects the largest reserve in the Atlantic, and private philanthropy sources. including engaging people, nature- joins the UK government’s Blue Belt To tackle the problem, Island based solutions for the UN Decade programme that aims to create 4 million It has the dual focus of facilitating Conservation carried out an island of Ecosystem Restoration, innovative square kilometres of marine protection the uptake of innovative financing eradication programme. The situation approaches and capacity-building, and across Overseas Territories. mechanisms, including private market- on Palmyra shows that the Chagos more. based investments focused on coral Archipelago is not alone in battling The Tristan da Cunha reserve will help reef conservation and restoration, and with invasive species and coconut The UK Overseas Territories protect 25 seabird species that breed unlocking finance for coral reef-related monoculture. Conservation Foundation has a long on the archipelago and will become a climate adaptation through the Green history in delivering conferences no-take reserve, meaning no fishing or Climate Fund, Adaptation Fund and Read more here about the Palmyra that provide a forum for government other potentially damaging activities will multilateral development banks. eradication, and how CCT plans to environmental bodies, NGOs and be permitted. adopt a similar approach for the 30 commercial organisations to discuss key Find out more here. rat-infested islands in the Chagos conservation issues, highlight success Read National Geographic’s story here. Archipelago here. stories, exchange ideas and forge

partnerships. © Jon Slayer Jon © For more information visit here.

10 11 A sanctuary for turtles 280,000 breeding pairs from 18 species, with Green and hawksbill turtle numbers have sooty tern, lesser noddy and red-footed booby continued to increase since the MPA was making up 96% of the birds found in the established. Between 2011 and 2018 the archipelago. estimated annual number of clutches of eggs for hawksbill turtles increased by up to five Red-footed boobies have been the subject of times, and for green turtles by up to nine GPS tracking that has revealed adult birds fly times since 1996. long distances to feed in deep water. Some pass the Great Chagos Bank but stay within Satellite tracking has shown that after green the MPA. One reason may be that the lack turtles finish nesting in the archipelago they of fishing within the MPA results in a high disperse across the Western Indian Ocean availability of food and reduces threats from (WIO) to forage. Some individuals have bycatch. ventured thousands of kilometres away to the waters of the Seychelles and mainland Africa. However, limitations on available breeding habitat due to the presences of invasive rats This data is being used to inform marine and some of the islands having previously spatial planning across the WIO and is an been used for coconut plantations continues example of how research from the MPA can to restrict seabird numbers. Currently 95% of A Decade in support important conservation actions, such land is unavailable to seabirds and therefore

©Chris Davies as determining boundaries of protected areas without addressing this issue the MPA cannot Review in the Seychelles. reach its full potential of being a seabird sanctuary. Helen Pitman, Director, Chagos In addition to collecting census and tracking Conservation Trust data, new foraging grounds in the form of CCT’s Healthy Islands, Healthy Reef seagrass meadows have been discovered, programme will tackle this problem. and it is hoped that future tracking will increase knowledge about the distribution of The above is a snapshot of the review that Scientists from the Bertarelli Programme of an increase in both access to the territory these important habitats across the whole explores in detail the impact on pelagic in Marine Science have reviewed a decade and investment in research. WIO. wildlife, crypto fauna diversity, key ongoing of lessons from one of the world’s largest threats and more. It is also only the Reef resilience marine reserves in recognition of the 10th A key role for seabirds beginning of a long-term commitment to The Chagos Archipelago is famed for its coral anniversary of the designation of British The Chagos Archipelago is home to one scientific research and conservation action reefs and is home to the world’s largest atoll Indian Ocean Territory Marine Protected million–or 5%–of the seabirds found across to support the Chagos Archipelago’s marine structure, the Great Chagos Bank. The review Area (MPA). the WIO. It is estimated there are over environment. found that the MPA was a valuable reference Published in Marine Biology, ‘A review of a site for understanding how coral communities decade of lessons from one of the worlds’ react to and that, despite largest MPAs: conservation gains and key being affected by climatic events such as the challenges’ looks at outcomes of the last 10 2015 and 2016 events, the years of marine research in the British Indian archipelago has not undergone the significant Ocean Territory. and continuing declines in health seen across other reefs in the Indian Ocean. Over 70 scientists, including a number of past and current CCT trustees, collaborated in the Scientists have determined that the lack of review that highlights a number of success additional local threats such as overfishing stories from the archipelago. and pollution sources, in addition to the remoteness of the archipelago, have also Marine research has been carried out in the enabled the reefs to recover faster from the © Jon Slayer Chagos Archipelago since the 1970s but bleaching events than elsewhere in the Indian there has been an explosion of scientific Ocean. expeditions in recent years, primarily because

12 13 © Jon Slayer Jon © Next Steps Towards a Rewilded Archipelago

Our large-scale island rewilding Using eDNA is one of these technologies as programme, Healthy Islands, Healthy discussed on P16. Reefs, has moved into phase two: research and development. Building the team

The Healthy Islands, Healthy Reefs Research Our ambitious programme requires a team and Development Project will provide that can ensure CCT has the expertise and CCT with the urgently needed knowledge funds to take it to the next phase. and capacity to deliver the rat eradication Building our rewilding team is an important component of the wider programme. step in the development phase. Researching the gaps Financing the future and engaging The feasibility study highlighted a number the public of knowledge gaps that need to be filled The rat eradication component alone is likely and, once gathered, this data will inform the to cost approximately £4 million, therefore Healthy Islands, Healthy Reefs Operational CCT needs to engage with the public about Plan. this important programme and ensure we can Questions over the presence or absence of finance it into the future. rats and mice on a few islands, the amount In 2021, CCT will launch its Healthy Islands, of bait crabs take, and what specialist Healthy Reefs programme with a fundraising requirements are needed for mangroves, all campaign to raise the funds required to start need to be addressed. the research and development phase. It is vital to have this information to maximise Together, with your support, we will secure the probability of successfully eradicating rats, the future of the Chagos Archipelago. which is key to rewilding the archipelago. We’re looking for donors and investors Investigating new technologies to make this vision a reality and secure We hope to look at which new technologies the future of this unique and spectacular could help not only monitor newly rat-free ecosystem. islands to make sure there are no future To donate please visit our website here. invasions, but also to record the return of seabirds to these islands as a measure of success.

14 15 Biodiversity monitoring is hugely valuable, the Chagos Archipelago and reached out and we rely on the resulting data for to NatureMetrics for advice on monitoring managing our natural world. The scientific firstly the presence of rats, and secondly the community has therefore set out to develop marine life in the Chagos Archipelago that is new ways to improve the speed at which we inextricably linked to the presence of seabird can collect biodiversity data, and improve the communities and rats. resolution at which we can detect different plants, animals and even microfauna. Both types of data could be used to inform long-term monitoring of the impact of invasive Here at NatureMetrics, we’re using a species, as well as the success of eradication biomonitoring method called environmental programmes and habitat restoration on the DNA metabarcoding. associated reef ecosystems of the islands.

Environmental DNA, or eDNA, is the DNA By identifying the challenge and approaching that is left in the environment by living things. NatureMetrics, CCT is now in a position to New Tools for Similar to a crime scene where humans readily generate big datasets that can impact leave their DNA behind, animals do the same real-world solutions. Monitoring whenever they interact with their habitat–even in the air. For more information on eDNA, Biodiversity metabarcoding and molecular techniques for © NatureMetrics © Whether it’s a fish swimming amongst a biodiversity monitoring please visit the Vere Ross-Gillespie, Regional coral reef, or an invasive rat foraging on land, NatureMetrics website or e-mail their team Coordinator & Molly Czachur, all living things leave traces of their DNA in directly - [email protected] and Science Communications Manager, the environment. We capture this DNA, using [email protected]. NatureMetrics the NatureMetrics filter pictured, and identify which animals are living where, and when.

We have had huge successes with using The British Indian Ocean Territory Marine reefs are less likely to thrive, and there are eDNA-based surveys for marine and Protected Area is famous for its size, yet many more wildlife relationships that are terrestrial life. From fishes to dolphins and at this scale the monitoring being threatened as biodiversity is lost. lizards to birds, we can capture biodiversity responsibilities present major logistical data for whole ecosystems just based on the and financial challenges. Conducting wide-scale spatial biodiversity surveys is a large undertaking, and doing DNA that the animals have left behind. At NatureMetrics, we are helping CCT them regularly adds another layer of costly In coral reefs, it’s possible to simply collect to establish new DNA-based biodiversity considerations. water samples from a boat and then send monitoring tools to increase the power of the the samples back to the lab, where we can data obtained and increase the pace at which Biodiversity monitoring and field surveys for tell you what DNA has been found in your it’s collected. marine and terrestrial habitats typically require teams of specialists being deployed to remote water sample. CCT has been proactively seeking novel locations, who then spend several weeks in This can describe coral reef health in a way ways to monitor the islands of the Chagos the field gathering data using conventional that is objective, rapid and reliable, especially Archipelago, namely due to 95% of the monitoring techniques (e.g. dive transects, when there is limited time or financial landmass being classed as degraded and BRUV, tagging, rodent trapping, camera resources. It’s these inventories of whole conventional monitoring methods being time trapping, fish netting, bird transects etc.). vertebrate communities that allow us to start consuming and costly. With a greater number of specialists needed understanding what lives in a system, and

The degradation is mostly caused by habitat in the field to identify and monitor a wide how it changes over time. © NatureMetrics © destruction and the presence of invasive range of taxonomic groups, the health and Having learned about these DNA-based rats, both resulting in a marked reduction safety risks to staff–as well as costs in methods, CCT saw the potential in using of biodiversity. Without healthy seabird terms of person days in the field–increase these methods for wide-scale monitoring of populations supplying nutrients, the coral exponentially.

16 17 The Chagos Archipelago is a rare haven of beautiful reefs, diverse wildlife and clean waters, located in the midst of the Indian Ocean. The Chagos Conservation Trust is the only UK charity dedicated to protecting it.

For more information please visit chagos-trust.org

If you would like to contribute to Chagos News please email [email protected]